Fluid apparatus



E. CANNON FLUID APPARATUS Filed Sept. 2'7. 19417 QN mvw M W WA mi :wl mmwmV/ 4 MRI, ,Qm W mm Q\ m MN W Jam 2% WLW atented Jan. 24, 1950 FLUIDAPPARATUS Earl Cannon, Downers Grove, 111., assignor to American SteelFoundries, Chicago, 111., a corporation of New Jersey 1 ApplicationSeptember 27, 1947, Serial No. 776,453

7 Claims.

This invention relates t hydraulic systems for supplying hydraulic fluidunder pressure and more particularly to a novel system for supplying anon-lubricating fluid under an adjustable predetermined pressure valueas, for example,

to a vessel to be tested under pressure.

Testing apparatus of the above type may be utilized to test large watervessels at pressures varying from five hundred to three thousand or morepounds per square inch with th pressure adjustable in small incrementssuch as two hundred pounds per square inch. In a system of this typewherein the adjustable pressure is maintained by a relief valve adaptedto discharge the pressure fluid at a predetermined value, rapid wearingof the valve seat not only increases maintenance costs but producesundesirable variations in pressure while the apparatus is in use.

It has been found that the use of accumulators to provide the adjustablepressure in a system of this type is undesirable inasmuch as theaccumulators are bulky and expensive.

Accordingly, a general object of the present invention is to providemeans in a system, such as above-described, for deliverin the fluidunder an adjustable predetermined pressure without utilizing anaccumulator and without blowing the non-lubricating hydraulic fluidthrough a relief valve.

Another object of the invention is to provide a novel pressureinterchanger device whereby the desired adjustable pressure on thenon-lubricating hydraulic fluid may be maintained by an hydraulic systemcontaining a lubricating fluid, such as oil.

Still another object of the invention is to provide novel means forautomatically charging the pressure interchanger with non-lubricatingfluid when the volume thereof in the interchanger device reaches apredetermined minimum value.

The foregoing and other objects and advantages of the invention willbecome apparent from a consideration of the following specification andthe accompanying drawing wherein the single figure is a flow diagram ofa novel hydraulic system embodyin the invention, in combination with anelectrical diagram illustrating the actuating circuits for the hydraulicsystem.

Describing the invention in detail, the interchanger device, generallydesignated l, comprises an oil cylinder 2 and a water cylinder 4preferably maintained in fixed relationship by bolts 6 connected to earsor lugs 8 on the cylinder 2 and to ears or lugs It on the cylinder 4.

An oil ram l2 reciprocates within the cylinder 2 and is operativelyconnected to a relatively small diameter Water ram l4 reciprocal withinthe cylinder 4. It will be understood that by means of this arrangement,a given pressure in the cylinder 2 develops a relatively great pressurewithin the .cylinder 4 for a purpose hereinafter described in detail.Thus the interchanger device is, in effect, an intensifier wherein therelatively large diameter ram I2 is eiiective to develop relativelygreat pressure within the cylinder 4.

The cylinder 4 is charged by a water pump I6 operated by a motor Hi, thesuction side of the pump being connected to a low pressure supply line Hand the discharge side of the pump being connected to a high pressuresupply line 20 connected to the cylinder 4 through a conventionalselector valve 22 adapted in the closed or discharge position thereof todirect fluid from the pump It to a discharge line 24. In the open ordelivery position thereof the valve 22 is operable to deliver pressurefluid from the pump 16 to the cylinder 4 through a one-way check valve28. The line 20 is also connected to a vessel 30 adapted to be testedunder the pressure of the water in the system and is preferablyconnected to a low pressure water supply line 32 equipped with a shutoff valve 34 whereby the vessel 30 may be filled with water from theline 32 before the system is put into operation, as hereinafterdescribed.

The motor I8 also operates an oil pump 35 having its suction sideconnected by a pipe 36 to a reservoir 38 of hydraulic fluid, such asoil, having lubricating qualities. The discharge side of the pump 35 isconnected to an oil supply line 40 which is connected to the cylinder 2and is preferably provided with a surge tank 42 equipped with aconventional stop cock 43.

The hydraulic pressure in the oil line 40 is maintained at an adjustablepredetermined value by a relief valve diagrammatically illustrated ascomprising a casing 44 with a port 46 communicating with a cylindricalchamber 48 containing a complementary piston 49 in slidable fluidtightengagement therewith. The piston is provided with a small port 50affording communication between the portions of the chamber 48 atopposite sides of the piston, and the piston is connected to a hollowstem 52 operable in its closed position to close the port 46. The stemis yieldingly urged to its closed position by a sprin 54.

The line 40 is connected to the chamber 48 at .the. side of the piston49 whereat the port 46 is disposed, whereupon movement of the stem 52 toits open position relieves pressure within the line 49 through a reliefor discharge line 55 connected to the port 46 and the reservoir 38. Theportion of the chamber 48 at the side of the piston 49 remote from theport 45 is provided with a port 56 connected to a port 58 of a pressureadjustor valve, generally designated 59, which determines the pressurevalue at which the relief valve stem 52 opens to accommodate dischargeof the hydraulic pressure in the line 40 through the line 55.

The valve 59, as diagrammatically illustrated, comprises a seat element6|] yieldingly urged to its closed position over the port 58 by a spring62 which is adjustably compressed by a stem 64 actuated by a cam 55rotatably mounted within a cylindrical housing 68 containing a springpressed friction block 59 for holding the cam 66 in any adjustedposition thereof to which the cam may be actuated by a handle extendingthrough a slot II in the housing 68.

The valve 59 is connected to the discharge line 55 by a branch line 13adapted to direct fluid from the port 58 to the line 55 when the valveelement 69 opens.

Thus it will be understood that the pressure in the line Ml is effectiveto open the stem 52 of the relief valve at a predetermined adjustablepressure value within a range, for example, of from five hundred tothree thousand pounds per square inch. The maximum pressure value withinthe line 49 is thus dependent upon the setting of the adjustor valve59.. It will be understood that the valves are diagrammaticallyillustrated and any conventional adjustable relief valve mechanism maybe utilized.

In operation of the system the vessel 39 to be tested is preferablyfilled with low pressure water from the line 32, and the adjustor valve59 is set to maintain a predetermined pressure value in the line 45 andthe cylinder 2.

The pumps iii and 35 are actuated by the motor I8 to direct oil andwater to the respective lines, 20 and 49. The valve 22 remains in closedor discharge position until an actuator 12 carried by an arm '55 mountedon the ram l2 engages a normall open switch 16 to close the same therebyclosin an electrical circuit through a conventional voltage supply l8,one terminal of which is connected at 80 to ground and through asolenoid coil 82 of a normally open double relay, generally designated84, and through a normally closed switch, generally designated 85, onecontact of which is connected at 88 to ground, the other contact of theswitch 86 being connected to the coil 82. Energization of the coil 82closes the normally open relay 84 thereby closing a holding circuit forthe coil 82 through contacts 90 and 92. Closing of the relay 84 alsocloses a circuit through contacts 93 and 94 and through the actuatingsolenoid coil 96 of the valve 22, one end of said coil being connectedat 98 to ground and the other end being connected to the contact 93.

Energization of the coil 96 actuates the valve 22 to its open oroperating position at which fluid from the water pump I6 is delivered tothe vessel 36 and the cylinder 4 urging the rams l2 and I l to the left,as seen in the drawing, thereby forcing oil in the line 49 through therelief valve and the relief or discharge line 55 into the reservoir 38.It may be noted in this connection that the construction of the reliefvalve is such that discharge therethrough of the fluid from the cylinder2 and the pump 35 at the same time does not materially increase themaximum pressure in the line 40.

When the ram l2 has reached its retracted position, at which time, thevolume of water in cylinder 4 is at a predetermined maximum value, theactuator 12 opens the normally closed switch 86 thereby breaking all ofthe above-mentioned electrical circuits whereupon the Valve 22 assumesits closed or discharge position whereat pressure fluid from the pump I5is discharged through the line 24. Under these conditions, make-up wateris supplied to the tested vessel 30 by the cylinder 4 at an adjustablepressure value predetermined by the maximum pressure in the line 59 andthe cylinder 2. Preferably the area of the ram I4 is smaller than theram l2, as above noted, so that a relatively low pressure within theline 40 is effective to maintain a relatively high pressure within thecylinder 4 and the tested vessel 39. Thus, for example, the rams arepreferably designed so that a pressure value of two thousand pounds persquare inch in the cylinder 2 is efiective to produce a pressure valueof three thousand pounds per square inch in the cylinder 4. However, theram areas may be equal, or either area may be greater, as desired.

As make-up water is supplied from the cylinder t, the ram it graduallymoves to its retracted position as the ram I2 advances until the switch16 is again closed whereupon the above-described cycle is repeated.

It may be noted that the relief valve associated with the line til isnot subjected to excessive wearing inasmuch as the hydraulic fluid inthis line is preferably a fluid, such as oil, having lubricatingqualities.

It is to be understood that I do not wish to be limited by the exactembodiment of the device shown which is merely by way of illustrationand not limitation as various and other forms of the device will, ofcourse, be apparent to those skilled in the art without departing fromthe spirit of the invention or the scope of the claims.

I claim:

1. A system of the class described comprising an intensifier with arelatively small chamber, a relatively large chamber, and interconnectedram means reciprocal within respective chambers, a line connected to thesmall chamber and adapted to supply hydraulic fluid under pressure to anassociated hydraulic device, pump means connected to said line forforcing said fluid therethrough, a pressure control line connected tothe large chamber, means for continuously delivering a differenthydraulic fluid to said control line at an adjustable predeterminedpressure value which controls the pressure in said small chamber, thepressure against the ram means in said small chamber exerted by the rammeans in said large chamber being at all times less than that deliv eredby said pump means to the small chamber, and means for automaticallysubjecting the small chamber to the pressure developed by said pumpmeans when the volume of hydraulic fluid in said small chamber reaches apredetermined minimum value and for automatically relieving said smallchamber from the pressure developed by said pump means when the volumeof hydraulic fluid in the small chamber reaches a predetermined maXimumvalue.

2. A system of the class described comprising a pressure interchangerincluding spaced chambers and ram means reciprocal therein, a lineconnected to one of said chambers and adapted to supply hydraulic fluidat a predetermined pressure value to associated means for utilizing saidfluid, means connected to said line for forcing an hydraulic fluidtherethrough, a pressure control line connected to the other chamber,means for continuously maintaining a diflerent hydraulic fluid at apredetermined pressure in said control line and for automaticallyexhausting the hydraulic fluid therefrom at a predetermined maximumpressure value lower than that developed by said pump means, and meansfor automatically subjecting said one chamber to the pressure developedby said pump means when the volume of hydraulic fluid in said onechamber reaches a predetermined minimum value and for automaticallyrendering said pump means ineffective to develop pressure in said onechamber when the volume of hydraulic fluid therein reaches apredetermined maximum value.

3. A system for supplying hydraulic fluid at a predetermined pressurevalue comprising a cylinder, a ram therein, means for developingpressure against said ram comprising an hydraulic motor including acylinder member and a ram member reciprocal therein, one of said membersbeing engaged with said ram, a source of hydraulic pressure fluidconnected to the cylinder member, means for automatically dischargingthe pressure from said source when the pressure in said cylinder memberreaches a predetermined maximum. value, a source of hydraulic fluid of adifferent character connected to said cylinder and adapted to deliversaid last-mentioned hydraulic fluid thereto at a pressure value greaterthan the first-mentioned value, and means for automatically renderingthe second-mentioned source ineffective when the volume of thelast-mentioned hydraulic fluid in said cylinder reaches a predeterminedmaximum value.

4. A system for supplying non-lubricating fluid under a predeterminedpressure comprising a pair of cylinders, a pair of abutting rams onereciprocal in each cylinder, a source of lubricating fluid underpressure connected to one cylinder, adjustable relief valve means fordischarging said lubricating fluid from said source at a predeterminedmaximum pressure value, means for supplying non-lubricating fluid to theother cylinder under a pressure greater than. said value, means forautomatically rendering said last-mentioned means ineffective when theram in said one cylinder is urged to a predetermined retracted positiontherein, a line connected to the other cylinder for delivering saidnon-lubricating fluid therefrom to associated means for utilizing saidnon- ]ubricating fluid.

5. A system of the class described comprising a pressure interchangerincluding spaced chambers and interconnected ram means reciprocal withinrespective chambers, a line connected to one of the chambers and adaptedto supply hydraulic fluid therefrom to associated means for utilizingsaid fluid, a pump, valve means connecting the discharge side of thepump to said one chamber, said valve means being adapted in one positionto deliver hydraulic fluid from the pump to said one chamber and beingadapted in another position to exhaust the output of said pump, apressure control line connected to the other chamber, means forcontinually maintaining a diflerent fluid at a predetermined pressure insaid control line and for automatically exhausting the fluid therefromat a predetermined maximum pressure value lower than that developed bysaid pump, means for automatically actuating said valve in to said oneposition thereof when the vole hydraulic fluid in said one chamberreaches a predetermined minimum value, and means for automaticallyactuating said valve means to said other position thereof when thevolume of hydraulic fluid in. said one chamber reaches a predetel minedmaximum value.

6. A system of class described comprising a cylinder adaptedto supplyfluid to associated means for utilizing the same, a ram in saidcylinder. hydraulic motor connected to said ram for advancing the sameinto said cylinder, a control line connected to said motor, a source oflubricating hydraulic pressure fluid connected to said line, reliefvalve means in said line for exhausting said fluid from said source at apredetermined maximum pressure value, means for charging the cylinderwith a pressure fluid of substantially non-lubricating character at apressure value greater than said first mentioned Value, said motor beingadapted to discharge fluid to said line accommodating movement of saidram from said cylinder when the pressure of the ram against the motorattains said value, and being adapted at other times to receive fluidfrom said line thereby advancing said ram into said cylinder and meansfor automatically rendering the second mentioned means ineffective whenthe volume of fluid in said cylinder reaches a predetermined value.

7. A system of the class described comprising an intensifier having arelatively small chamber, a relatively large chamber and interconnectedram means reciprocal within respective chambers, said small chamberbeing adapted to supply fluid under pressure to associated means forutilizing said fluid, pump means connected to said small chamber fordelivering said fluid thereto, a pressure control line connected to thelarge chamber, means for continuously delivering pressure fluid to saidcontrol line at an adjustable predetermined pressure value, the pressureagainst the ram' means in said small chamber exerted by the ram means insaid large chamber being at all times less than that delivered by saidpump means to the small chamber, and means for automatically renderingsaid pump means ineffective to deliver hydraulic fluid to the smallchamber when the volume of fluid therein reaches a predetermined maximumvalue.

EARL CANNON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

